It's been coooold here, teens to low 20's. Noticed that when I turn the steering wheel on my '04 4.7 crew cab that the movement is choppy. Smooth move and then a feeling of no assist back to smooth with only what seems to be split seconds of lost assist. Fluid level is correct, belt tension correct. Anyone know if it's the pump, steering mechanism or fluid problem? Steering seems stiff too, doesn't return to center without help and all problems remain after total warm up of the truck. ????

 

First check and make sure nothing in the steering is binding. Then I might consider doing a fluid flush, and see if that doesn't improve anything.

 

I doubt it is the power steering. It's more likely the lower intermediate shaft.
After a while the bearings dry up and you'll notice binding.

 

It only happens when it's cold, goes away once it warms up. Unfamiliar with the "intermediate shaft" terminology. How would I check and/or repair/replace?

 

Shaft between the steering column, and steering box.

 

Mine was stiff for a while when cold then would loosen up as the temps warmed.
Almost felt as if the truck would bind coming out of a turn.

 

Fwiw, 84-96 corvettes have a similar problem. It was called "morning sickness"
Usually a fluid flush with a synthetic fluid fixed it.